Trac configuration is done by editing the trac.ini config file, located in <projectenv>/conf/trac.ini.

Global Configuration

Since version 0.9, Trac can also read the configuration from a global trac.ini file. These global options will then be merged with the environment-specific options, where local options override global options.

The global configuration is by default localted in $prefix/share/trac/conf/trac.ini. It can be moved to a different location (for example, /etc/trac.ini), but that requires changing the file trac/siteconfig.py which gets created when Trac is installed.

Reference

This is a brief reference of available configuration options.

[account-manager]

account_changes_notify_addresses

List of email addresses that get notified of user changes, ie,
new user, password change and delete user.

authentication_url

force_passwd_change

Force the user to change password when it's reset.

generated_password_length

Length of the randomly-generated passwords created when resetting the password for an account.

Path to the users file. Leave blank to locate the users file by reading svnserve.conf

password_format

password_store

persistent_sessions

Allow the user to be remembered across sessions without needing to re-authenticate. This is, user checks a "Remember Me" checkbox and, next time he visits the site, he'll be remembered

reset_password

Set to false if there is no email system setup.

[attachment]

max_size

Maximum allowed file size (in bytes) for ticket and wiki
attachments.

render_unsafe_content

Whether attachments should be rendered in the browser, or
only made downloadable.
Pretty much any file may be interpreted as HTML by the browser,
which allows a malicious user to attach a file containing cross-site
scripting attacks.
For public sites where anonymous users can create attachments it is
recommended to leave this option disabled (which is the default).

[browser]

color_scale

Enable colorization of the age column.
This uses the same color scale as the source code annotation:
blue is older, red is newer.
(since 0.11)

downloadable_paths

List of repository paths that can be downloaded.
Leave the option empty if you want to disable all downloads, otherwise
set it to a comma-separated list of authorized paths (those paths are
glob patterns, i.e. "*" can be used as a wild card)
(since 0.10)

hide_properties

Comma-separated list of version control properties to hide from
the repository browser.
(since 0.9)

intermediate_color

(r,g,b) color triple to use for the color corresponding
to the intermediate color, if two linear interpolations are used
for the color scale (see intermediate_point).
If not set, the intermediate color between oldest_color and
newest_color will be used.
(since 0.11)

intermediate_point

If set to a value between 0 and 1 (exclusive), this will be the
point chosen to set the intermediate_color for interpolating
the color value.
(since 0.11)

newest_color

(r,g,b) color triple to use for the color corresponding
to the newest color, for the color scale used in blame or
the browser age column if color_scale is enabled.
(since 0.11)

oldest_color

(r,g,b) color triple to use for the color corresponding
to the oldest color, for the color scale used in blame or
the browser age column if color_scale is enabled.
(since 0.11)

oneliner_properties

Comma-separated list of version control properties to render
as oneliner wiki content in the repository browser.
(since 0.11)

render_unsafe_content

Whether attachments should be rendered in the browser, or
only made downloadable.
Pretty much any file may be interpreted as HTML by the browser,
which allows a malicious user to attach a file containing cross-site
scripting attacks.
For public sites where anonymous users can create attachments it is
recommended to leave this option disabled (which is the default).

wiki_properties

Comma-separated list of version control properties to render
as wiki content in the repository browser.
(since 0.11)

[changeset]

max_diff_bytes

Maximum total size in bytes of the modified files (their old size
plus their new size) for which the changeset view will attempt to show
the diffs inlined (since 0.10).

max_diff_files

Maximum number of modified files for which the changeset view will
attempt to show the diffs inlined (since 0.10).

wiki_format_messages

Whether wiki formatting should be applied to changeset messages.
If this option is disabled, changeset messages will be rendered as
pre-formatted text.

[header_logo]

alt

Alternative text for the header logo.

height

Height of the header logo image in pixels.

link

URL to link to from header logo.

src

URL of the image to use as header logo.

width

Width of the header logo image in pixels.

[inherit]

plugins_dir

Path of the directory containing additional plugins.
Plugins in that directory are loaded in addition to those in the
directory of the environment plugins, with this one taking
precedence.
(since 0.11)

templates_dir

Path to the shared templates directory.
Templates in that directory are loaded in addition to those in the
environments templates directory, but the latter take precedence.
(since 0.11)

[logging]

log_file

If log_type is file, this should be a path to the log-file.

log_format

Custom logging format.
If nothing is set, the following will be used:
Trac[$(module)s] $(levelname)s: $(message)s
In addition to regular key names supported by the Python logger library
library (see http://docs.python.org/lib/node422.html), one could use:
- $(path)s the path for the current environment
- $(basename)s the last path component of the current environment
- $(project)s the project name
Note the usage of $(...)s instead of %(...)s as the latter form
would be interpreted by the ConfigParser? itself.
Example:
($(thread)d) Trac[$(basename)s:$(module)s] $(levelname)s: $(message)s
(since 0.10.5)

log_level

Level of verbosity in log.
Should be one of (CRITICAL, ERROR, WARN, INFO, DEBUG).

log_type

Logging facility to use.
Should be one of (none, file, stderr, syslog, winlog).

[milestone]

stats_provider

Name of the component implementing ITicketGroupStatsProvider,
which is used to collect statistics on groups of tickets for display
in the milestone views.

[mimeviewer]

enscript_modes

List of additional MIME types known by Enscript.
For each, a tuple mimetype:mode:quality has to be
specified, where mimetype is the MIME type,
mode is the corresponding Enscript mode to be used
for the conversion and quality is the quality ratio
associated to this conversion.
That can also be used to override the default
quality ratio used by the Enscript render, which is 2
(since 0.10).

enscript_path

Path to the Enscript executable.

max_preview_size

Maximum file size for HTML preview. (since 0.9).

mime_map

List of additional MIME types and keyword mappings.
Mappings are comma-separated, and for each MIME type,
there's a colon (":") separated list of associated keywords
or file extensions. (since 0.10).

php_path

Path to the PHP executable (since 0.9).

tab_width

Displayed tab width in file preview (since 0.9).

[notification]

admit_domains

Comma-separated list of domains that should be considered as
valid for email addresses (such as localdomain)

always_notify_owner

Always send notifications to the ticket owner (since 0.9).

always_notify_reporter

Always send notifications to any address in the reporter
field.

always_notify_updater

Always send notifications to the person who causes the ticket
property change.

ignore_domains

Comma-separated list of domains that should not be considered
part of email addresses (for usernames with Kerberos domains)

mime_encoding

Specifies the MIME encoding scheme for emails.
Valid options are 'base64' for Base64 encoding, 'qp' for
Quoted-Printable, and 'none' for no encoding. Note that the no encoding
means that non-ASCII characters in text are going to cause problems
with notifications (since 0.10).

Email address(es) to always send notifications to,
addresses can be seen by all recipients (Cc:).

smtp_default_domain

Default host/domain to append to address that do not specify one

smtp_enabled

Enable SMTP (email) notification.

smtp_from

Sender address to use in notification emails.

smtp_from_name

Sender name to use in notification emails.

smtp_password

Password for SMTP server. (since 0.9).

smtp_port

SMTP server port to use for email notification.

smtp_replyto

Reply-To address to use in notification emails.

smtp_server

SMTP server hostname to use for email notifications.

smtp_subject_prefix

Text to prepend to subject line of notification emails.
If the setting is not defined, then the [$project_name] prefix.
If no prefix is desired, then specifying an empty option
will disable it.(since 0.10.1).

smtp_user

Username for SMTP server. (since 0.9).

ticket_subject_template

A Genshi text template snippet used to get the notification subject.
(since 0.11)

use_public_cc

Recipients can see email addresses of other CC'ed recipients.
If this option is disabled (the default), recipients are put on BCC
(since 0.10).

use_short_addr

Permit email address without a host/domain (i.e. username only)
The SMTP server should accept those addresses, and either append
a FQDN or use local delivery (since 0.10).

use_tls

Use SSL/TLS to send notifications (since 0.10).

[project]

admin

E-Mail address of the project's administrator.

descr

Short description of the project.

footer

Page footer text (right-aligned).

icon

URL of the icon of the project.

name

Name of the project.

url

URL of the main project web site, usually the website in which
the base_url resides.

[query]

default_anonymous_query

The default query for anonymous users.

default_query

The default query for authenticated users.

items_per_page

Number of tickets displayed per page in ticket queries,
by default (since 0.11)

[report]

items_per_page

Number of tickets displayed per page in ticket reports,
by default (since 0.11)

By how many points an BlogSpam? reject impacts the overall karma of
a submission.

blogspam_skip_tests

Comma separated list of tests to skip.

captcha

CAPTCHA method to use for verifying humans.

captcha_expression_ceiling

Maximum value of individual terms in numeric CAPTCHA
expression.

captcha_expression_terms

Number of terms in numeric CAPTCHA expression.

captcha_karma

By how many points a successful CAPTCHA response increases the
overall score.

captcha_karma_lifetime

Time in seconds that a successful CAPTCHA response increases
karma.

captcha_recaptcha_private_key

Private key for recaptcha usage..

captcha_recaptcha_public_key

Public key for recaptcha usage..

extlinks_allowed_domains

List of domains that should be allowed in external links

extlinks_karma

By how many points too many external links in a submission impact
the overall score.

ip_throttle_karma

By how many points exceeding the configured maximum number of posts
per hour impacts the overall score.

is_forwarded

Interpret X-Forwarded-For header for IP checks.

logging_enabled

Whether all content submissions and spam filtering activity should
be logged to the database.

max_external_links

The maximum number of external links allowed in a submission until
that submission gets negative karma.

max_posts_by_ip

The maximum allowed number of submissions per hour form a single IP
address. If this limit is exceeded, subsequent permissions get negative
karma.

min_karma

The minimum score required for a submission to be allowed.

purge_age

The number of days after which log entries should be purged.

regex_karma

By how many points a match with a pattern on the BadContent? page
impacts the overall karma of a submission.

reject_handler

The handler used to reject content.

session_karma

By how many points an existing and configured session improves the
overall karma of the submission. A third of the points is granted for
having an existing session at all, the other two thirds are granted
when the user has his name and/or email address set in the session,
respectively.

show_blacklisted

Show the matched bad content patterns in rejection message.

train_external

Allow training of external services.

trust_authenticated

Whether content submissions by authenticated users should be trusted
without checking for potential spam or other abuse.

By how many points an TypePad? reject impacts the overall karma of
a submission.

use_external

Allow usage of external services.

[svn]

branches

List of paths categorized as branches.
If a path ends with '*', then all the directory entries found
below that path will be included.

tags

List of paths categorized as tags.
If a path ends with '*', then all the directory entries found
below that path will be included.

[ticket]

default_cc

Default cc: list for newly created tickets.

default_component

Default component for newly created tickets.

default_description

Default description for newly created tickets.

default_keywords

Default keywords for newly created tickets.

default_milestone

Default milestone for newly created tickets.

default_owner

Default owner for newly created tickets.

default_priority

Default priority for newly created tickets.

default_resolution

Default resolution for resolving (closing) tickets
(since 0.11).

default_severity

Default severity for newly created tickets.

default_summary

Default summary (title) for newly created tickets.

default_type

Default type for newly created tickets (since 0.9).

default_version

Default version for newly created tickets.

max_description_size

Don't accept tickets with a too big description.
(since 0.11).

preserve_newlines

Whether Wiki formatter should respect the new lines present
in the Wiki text.
If set to 'default', this is equivalent to 'yes' for new environments
but keeps the old behavior for upgraded environments (i.e. 'no').
(since 0.11).

Ordered list of workflow controllers to use for ticket actions
(since 0.11).

[timeline]

abbreviated_messages

Whether wiki-formatted event messages should be truncated or not.
This only affects the default rendering, and can be overriden by
specific event providers, see their own documentation.
(Since 0.11)

changeset_collapse_events

Whether consecutive changesets from the same author having
exactly the same message should be presented as one event.
That event will link to the range of changesets in the log view.
(since 0.11)

changeset_long_messages

Whether wiki-formatted changeset messages should be multiline or not.
If this option is not specified or is false and wiki_format_messages
is set to true, changeset messages will be single line only, losing
some formatting (bullet points, etc).

changeset_show_files

Number of files to show (-1 for unlimited, 0 to disable).
This can also be location, for showing the common prefix for the
changed files. (since 0.11).

default_daysback

Default number of days displayed in the Timeline, in days.
(since 0.9.)

max_daysback

Maximum number of days (-1 for unlimited) displayable in the
Timeline. (since 0.11)

newticket_formatter

Which formatter flavor (e.g. 'default' or 'oneliner') should be
used when presenting the description for new tickets.
If 'oneliner', the [timeline] abbreviated_messages option applies.
(since 0.11).

ticket_show_details

Enable the display of all ticket changes in the timeline
(since 0.9).

[trac]

Reference URL for the Trac deployment.
This is the base URL that will be used when producing documents that
will be used outside of the web browsing context, like for example
when inserting URLs pointing to Trac resources in notification
e-mails.

check_auth_ip

Whether the IP address of the user should be checked for
authentication (since 0.9).

Name of the component that handles requests to the base URL.
Options include TimelineModule, RoadmapModule, BrowserModule,
QueryModule, ReportModule and TicketModule (since 0.9).

default_timezone

The default timezone to use

htdocs_location

Base URL of the core static resources.

ignore_auth_case

Whether login names should be converted to lower case
(since 0.9).

mainnav

Order of the items to display in the mainnav navigation bar,
listed by IDs. See also TracNavigation.

metanav

Order of the items to display in the metanav navigation bar,
listed by IDs. See also TracNavigation.

permission_policies

List of components implementing IPermissionPolicy, in the order in
which they will be applied. These components manage fine-grained access
control to Trac resources.
Defaults to the DefaultPermissionPolicy? (pre-0.11 behavior) and
LegacyAttachmentPolicy? (map ATTACHMENT_* permissions to realm specific
ones)

permission_store

Name of the component implementing IPermissionStore, which is used
for managing user and group permissions.

repository_dir

Path to local repository. This can also be a relative path
(since 0.11).

Timeout value for database connection, in seconds.
Use '0' to specify no timeout. (Since 0.11)

use_base_url_for_redirect

Optionally use [trac] base_url for redirects.
In some configurations, usually involving running Trac behind a HTTP
proxy, Trac can't automatically reconstruct the URL that is used to
access it. You may need to use this option to force Trac to use the
base_url setting also for redirects. This introduces the obvious
limitation that this environment will only be usable when accessible
from that URL, as redirects are frequently used. (since 0.10.5)

[wiki]

Enable/disable the use of unsafe HTML tags such as <script> or
<embed> with the HTML WikiProcessor
(since 0.10.4).
For public sites where anonymous users can edit the wiki it is
recommended to leave this option disabled (which is the default).

[components]

(since 0.9)

This section is used to enable or disable components provided by plugins, as well as by Trac itself. The component to enable/disable is specified via the name of the option. Whether its enabled is determined by the option value; setting the value to enabled or on will enable the component, any other value (typically disabled or off) will disable the component.

The option name is either the fully qualified name of the components or the module/package prefix of the component. The former enables/disables a specific component, while the latter enables/disables any component in the specified package/module.

The first option tells Trac to disable the report module. The second option instructs Trac to enable all components in the webadmin package. Note that the trailing wildcard is required for module/package matching.

See the Plugins page on About Trac to get the list of active components (requires CONFIG_VIEWpermissions.)